LEAP

247 views | 3 messages Discussion: LEAP
Topic: Is there a CO2 emission ceiling by default in LEAP?Subscribe | Previous | Next

Junling Liu 9/2/2016

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Hi, I'm using optimization to calculate the Electricity Generation model along with other demand models for China. To mu surprise, I found that the total CO2 emissions would never surpass 10,000 Mt no matter how many energy is consumed in the future(however the current CO2 emissions in China is already more than 9000 Mt, which means it will reach this gate very soon). Whenever the total emission reaches 10,000 Mt, it will never increase again even with energy consumption keep growing in the future. I didn't check "Enable Emissions Constraints" in Basic Parameters and there is no "Effect" module in my analysis.

I'm very curious about how this is happening. This "emission constraint" is definitely influencing the results of my analysis, such as scenarios consuming more energy will have much higher rate of electricity generated from renewables while scenarios with less energy demand will consume more fossil fuel as a result of the "emission cap". All the parameters and values are set the same for those scenarios.

Looking forward to your reply.

Best,

LIU Junling

Emily Ghosh 9/2/2016

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Hi Junling,

Thanks for your post. As a start, we recommend reviewing the inputs and outputs from the model in a step-by-step manner to investigate what the cause of this emissions constraint may be.

First, check if it is the whole model that appears to have an emissions constraint or just the electricity generation module. If it is just the electricity generation module, review electricity production. If the outputs appear constrained, review if there are any restrictions to the module and output fuel requirements. If not, check if there is enough available capacity and that the processes are being dispatched correctly. Also, review the production by imported fuels and renewable processes, since they may not have an emissions associated with them. If the outputs are not constrained over time, check the inputs, and eventually check to make sure that correct emission factor expressions and methods are assigned to each of the processes.

If it is the whole model that appears constrained, review the other transformation modules in a similar manner as described above. If no constraints are apparent for the transformation branches, go through the demand branches. Review the final energy demands to see if there are any constraints. Then review the inputs including energy intensities and verify the emission factors.

If you have any other questions or are still experiencing an issue, please let us know.

Best regards,

Emily

Junling Liu 9/7/2016

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Hi Emily,

According to your suggestions, I've looked through my model step-by-step. It's very clear that there is no emission constrains on demand since emissions are increasing with more energy consumed under different scenarios.

However, when it comes to electricity generation module (by using optimization method), the processes dispatched result and emissions are of great difference. Though with almost the same electricity demands in two scenarios, the one scenario with a bit more power demand will introduce a lot new coal fire plants in the future while the less power demand scenario results in no coal plants additions but make the most use of renewable energy (such as wind, solar PV, both reach the maximum annual additions). These two scenarios have totally the same settings for electricity generation module. In addition, both scenarios result in electricity imports even there are surplus capacity that could be added to fill this gap. I also put an extremely high cost on import of electricity, but it didn't work. I really don't know what's wrong with it...

For a better discussion, I've sent a back up of my model to your email(emily.ghosh@sei-us.org) from hycocokiki@163.com. Grateful if you could have a look on it and let me know what's the problems. Thank you very much.

Best,

LIU Junling